1. Field of the Invention
The present invention pertains to delivery systems for the localized administration of a medicament to the upper respiratory tract and medicated compositions containing the delivery systems. The system comprises (a) a safe and effective amount of a medicament useful for treating the upper respiratory tract; (b) an ionic polysaccharide; and, (c) a cross-linking agent. This invention also relates to methods for preparing and using the delivery systems and compositions.
2. Description of the Background
Pharyngitis, the acute inflammation of the pharnyx, is characterized, inter alia, by sore throat and painful swallowing. Painful swallowing is also often associated with laryngitis, the inflammation of the larynx. Patients suffering from sore throat and painful swallowing seek medication which can provide rapid onset of relief as well as sustained local action. Present therapeutic lozenge formulations do not provide sustained local therapeutic effects because of salivary dilution and rapid swallowing. Moreover, anesthetic-type lozenges tend to have a numbing effect on the entire mouth and tongue area and are not targeted to the oral pharyngeal area.
Various materials and techniques have been used to trap active ingredients and control their release. U.S. Pat. No. 4,695,463 discloses a particulate delivery system comprising an insolubilized active ingredient selected from the group consisting of flavoring agents, drugs, coloring agents, sweetening agents, perfumes, and bulking agents, entrapped in a cross-linked alginate or carrageenate matrix.
U.S. Pat. No. 5,330,761 discloses a controlled release, solid tablet comprising a bioadhesive mixture of a heterodisperse gum matrix and a bioadhesive agent selected from the group consisting of carbomer, polycarbophil and polyethylene oxide combined with an inert diluent and an active ingredient.
U.S. Pat. No. 5,147,648 discloses the improved adherence of gels to the mucous membranes by the separate application to the same area two components capable of forming a gel such as a metallic salt and a polysaccharide. One of the two components is used as a carrier for medicaments.
U.S. Pat. No. 4,843,098 discloses an ingestible substantially anhydrous aggregate comprising a pre-s welled hydrocolloid which partially entraps and binds a drug substrate. The hydrocolloid is selected from the group consisting of carboxymethyl cellulose, methyl cellulose, karaya gum, acacia gum, sodium alginate, calcium alginate, and hydroxypropyl methyl cellulose. The substrate is selected from the group consisting of potassium chloride, calcium carbonate, magnesium oxide, cholestyramine, and N-acetyl procainamide.
U.S. Pat. No. 4,857,331 discloses a sugarless ingestible gel confectionery delivery system comprising by weight of the final delivery system (a) a pectin gel component in an amount from about 1% to about 5%, (b) an algin gel component in an amount from about 0.2% to about 1.5%, (c) a polymer network gel component in an amount of up to about 5%, and (d) an edible insoluble solid in an amount sufficient to strengthen the internal gel network such that the gel retains its structural integrity during mold removal.
U.S. Pat. No. 4,981,698 discloses a sweetener delivery system comprising (a) a first solid natural or artificial high intensity sweetener; (b) a first inner coating selected from hydrophobic and hydrophobic coating materials, wherein the inner coating and first sweetener are mixed and prepared to form a core; and (c) a second outer coating of a hydrophobic polymer containing a second sweetener. The second outer coating is selected from the group consisting of gum arabic, tragacanth, karaya, ghatti, agar, alginates, carrageenans, furcellaran, and psyllium.
U.S. Pat. No. 5,004,595 discloses a free-flowing particulate delivery system comprising (a) a core comprising a flavor in particulate form; and (b) an encapsulating matrix for the core, wherein the matrix comprises an outer coating of a hydrophobic polymer containing an intense sweetener. The outer coating is selected from the group consisting of gum arabic, tragacanth, karaya, ghatti, agar, alginates, carrageenans, furcellaran, and psyllium.
While the above compositions provide various means for controlling the release of ingredients, none of the above compositions are entirely satisfactory for the targeted localized administration of a medicament to the upper respiratory tract.